Originally Posted by ♣Zen31ZR♣

I don't really trust Ebay manual boost controllers, you never know exactly how it will work...... The one I purchased from a legit source has worked perfectly for over a year.
And your friend is somewhat correct, but you should have a boost guage with any boost controller you use. The difference between safe psi and engine damage (at least on the stock fuel system) is about 3 psi, you really want to know exactly what is going on in your engine at all times. Get a boost guage no matter what controller you use.

What brands are these boost controllers you've seen on Ebay? Are they used or new? I certainly would never buy a used MBC off Ebay. $15 is not worth a blown engine.....